Actuator device

ABSTRACT

An actuator device includes a support portion, a movable portion, a connection portion which connects the movable portion to the support portion on a second axis, a first wiring which is provided on the connection portion, a second wiring which is provided on the support portion, and an insulation layer which includes a first opening exposing a surface opposite to the support portion in a first connection part located on the support portion in one of the first wiring and the second wiring and covers a corner of the first connection part. The rigidity of a first metal material forming the first wiring is higher than the rigidity of a second metal material forming the second wiring. The other wiring of the first wiring and the second wiring is connected to the surface of the first connection part in the first opening.

TECHNICAL FIELD

The present disclosure relates to an actuator device configured as, forexample, a micro electro mechanical systems (MEMS) device.

BACKGROUND ART

As an MEMS device, there is known an actuator device including a supportportion, a movable portion, a connection portion connecting the movableportion to the support portion on a predetermined axis so that themovable portion is swingable about the axis, and wirings provided on theconnection portion and the support portion. In such an actuator device,for example, there are cases in which the movable portion is oscillatedat a high speed corresponding to a resonance frequency level (severalkHz to several tens of kHz). In such a case, because metal fatigueoccurs in the wiring on the connection portion, there is concern thatcharacteristics may be deteriorated and disconnection may occur.

In order to solve the above-described problems, there is proposed atechnique in which a first wiring formed of a high-rigid metal materialis provided on a connection portion and the first wiring is electricallyconnected to a second wiring formed of a low-rigid metal material in alow-stress region on a support portion (for example, sec PatentLiterature 1).

CITATION LIST Patent Literature

Patent Literature 1: U.S. Pat. No. 8,218,218

SUMMARY OF INVENTION Technical Problem

The present inventor has found that it is possible to further suppressdeterioration of wirings provided on the connection portion and thesupport portion by contriving an electric connection structure betweenthe first wiring and the second wiring in addition to disposing theelectric connection position between the first wiring and the secondwiring on the support portion.

An object of an embodiment of the present disclosure is to provide anactuator device capable of suppressing deterioration of wirings providedon a connection portion and a support portion.

Solution to Problem

An actuator device according to an embodiment of the present disclosureincludes: a support portion; a movable portion; a connection portionwhich connects the movable portion to the support portion on apredetermined axis so that the movable portion is swingable about theaxis; a first wiring which is provided on the connection portion; asecond wiring which is provided on the support portion; and aninsulation layer which includes a first opening exposing a surfaceopposite to the support portion in a first connection part located onthe support portion in one wiring of the first wiring and the secondwiring and covers a corner of the first connection part, in whichrigidity of a first metal material forming the first wiring is higherthan rigidity of a second metal material forming the second wiring, andin which the other wiring of the first wiring and the second wiring isconnected to the surface of the first connection part in the firstopening.

In the actuator device, the rigidity of the first metal material formingthe first wiring provided on the connection portion is higher than therigidity of the second metal material, forming the second wiringprovided on the support portion. Accordingly, deterioration of the firstwiring provided on the connection portion is suppressed. Also,deformation (curving or the like) of the support portion caused when allof the wirings provided on the connection portion and the supportportion are formed of a high-rigid metal material is also suppressed.Further, the first wiring and the second wiring are connected to eachother at the first connection part located on the support portion.Accordingly, because stress applied to the first connection part isreduced, deterioration of the first connection part is suppressed.Further, the corner of the first connection part is covered by theinsulation layer and the first wiring and the second wiring areconnected to each other in the surface opposite to the support portionin the first connection part exposed by the first opening of theinsulation layer. Accordingly, because stress applied from the firstwiring to the second wiring is reduced by the insulation layer,deterioration of the second wiring formed of the second metal materialhaving rigidity lower than that of the first metal material issuppressed. Thus, according to the actuator device, it is possible tosuppress deterioration of the wirings provided on the connection portionand the support portion.

In the actuator device according to an embodiment of the presentdisclosure, the first connection part may be separate from the axis by apredetermined distance. According to this configuration, it is possibleto suppress stress applied to the first connection part while securing aregion for providing another configuration on the support portion.

In the actuator device according to an embodiment of the presentdisclosure, the distance may be larger than ½ times a minimum width ofthe connection portion. According to this configuration, it is possibleto further reduce stress applied to the first connection part whilesecuring a region for providing another configuration on the supportportion.

In the actuator device according to an embodiment of the presentdisclosure, a cross-sectional area of the first wiring may be largerthan a cross-sectional area of the second wiring. According to thisconfiguration, it possible to suppress an increase in resistance valueof the first wiring even when the resistivity of the first metalmaterial is higher than that of the second metal material.

In the actuator device according to an embodiment of the presentdisclosure, a width of the first wiring may be larger than a width ofthe second wiring. According to this configuration, it is possible tosuppress an increase in resistance value of the first wiring by securingthe cross-sectional area of the first wiring while suppressing thetorsion of the connection portion from being obstructed.

In the actuator device according to an embodiment of the presentdisclosure, the first opening may be separate from the corner of thefirst connection part. According to this configuration, it is possibleto reliably reduce stress applied from the first wiring to the secondwiring.

In the actuator device according to an embodiment of the presentdisclosure, a region corresponding to the corner of the first connectionpart in a surface opposite to the support portion in the insulationlayer may be curved in a convex shape toward the opposite side to thesupport portion. According to this configuration, it is possible tofurther reduce stress applied from the first wiring to the secondwiring.

The actuator device according to an embodiment of the present disclosuremay further include a coil which is provided with the movable portion; amagnetic field generator which applies a magnetic field to the coil; anda third wiring which is provided on the movable portion and iselectrically connected to the coil, in which the insulation layer mayinclude a second opening exposing a surface opposite to the movableportion in a second connection part located on the movable portion inone wiring of the first wiring and the third wiring and cover a cornerof the second connection part, in which rigidity of the first metalmaterial may be higher than rigidity of a third metal material formingthe third wiring, and in which the other wiring of the first wiring andthe third wiring may be connected to the surface of the secondconnection part in the second opening. According to this configuration,it is possible to suppress deterioration of the wirings provided on theconnection portion and the movable portion.

The actuator device according to an embodiment of the present disclosuremay further include a frame which supports the support portion and themovable portion, in which the support portion is connected to the frameto be swingable about an axis intersecting the axis. According to thisconfiguration, it is possible to swing the movable portion about each oftwo orthogonal axes.

The actuator device according to an embodiment of the present disclosuremay further include a mirror which is provided with the movable portion.According to this configuration, it is possible to use the mirror forthe light scanning or the like by swinging the mirror about the axis.

Advantageous Effects of Invention

According to an embodiment of the present disclosure, it is possible tosuppress deterioration of the wirings provided on the connection portionand the support portion.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of an actuator device according to anembodiment of the present disclosure.

FIG. 2 is a plan view of a circuit configuration of the actuator deviceof FIG. 1.

FIG. 3 is a partially enlarged view of FIG. 2.

FIG. 4 is a cross-sectional view taken along a line IV-IV of FIG. 3.

FIG. 5 is a cross-sectional view taken along a line V-V of FIG. 3.

FIG. 6 is a cross-sectional view of a first connection part of anactuator device of a first modified example.

FIG. 7 is a cross-sectional view of a first connection part of anactuator device of a second modified example.

FIG. 8 is a partially enlarged view of an actuator device of a thirdmodified example.

DESCRIPTION OF EMBODIMENT

Hereinafter, an embodiment of the present disclosure will be describedin detail with reference to the drawings. In the following description,the same reference numerals will be used for the same or correspondingcomponents and a repetitive description will be omitted.

As illustrated in FIGS. 1 and 2, an actuator device 1 includes a mirror2, a magnetic field generator 3, a frame 4, a support portion 5, amovable portion 6, a pair of connection portions 7, and a pair ofconnection portions 8. The actuator device 1 is configured as an MEMSdevice which swings the mirror 2 about each of a first axis XL and asecond axis X2 which are orthogonal to each other. Such an actuatordevice 1 is used in, for example, an optical switch or optical scanner.

The mirror 2 is a light reflection film formed by a metal film. Themirror 2 has a circular shape in the plan view (when viewed from adirection orthogonal to a plane in which at least the support portion 5,the movable portion 6, and the pair of connection portions 7 arearranged). A metal material forming the mirror 2 is, for example,aluminum (Al), gold (Au), or silver (Ag).

The magnetic field generator 3 is a rectangular flat plate and includesa pair of main surfaces. The magnetic field generator 3 applies amagnetic field to a coil 11 provided with the support portion 5 and acoil 12 provided with the movable portion 6 (the coils 11 and 12 will bedescribed later). The magnetic field generator 3 is configured as, forexample, a permanent magnet or the like. The array of the magnetic polesof the magnetic field generator 3 is, for example, a Halbach array.

The frame 4 is a flat plate-shaped frame having a rectangular shape inthe plan view. The frame 4 is disposed on one main surface of themagnetic field generator 3. The frame 4 supports the support portion 5,the movable portion 6, and the mirror 2 via the pair of connectionportions 7. Each connection portion 7 connects the support portion 5 tothe frame 4 on the first axis X1 so that the support portion 5 isswingable about the first axis X1. That is, each connection portion 7serves as a torsion bar. Each connection portion 7 is formed in anS-shape in the plan view in order to improve the strength and facilitatethe adjustment of the torsion spring constant.

The support portion 5 is a flat plate-shaped frame having a rectangularshape in the plan view and is located at the inside of the frame 4. Thesupport portion 5 is disposed to face one main surface of the magneticfield generator 3 and to be separate from one main surface of themagnetic field generator 3. The support portion 5 supports the movableportion 6 and the mirror 2 via the pair of connection portions 8. Eachconnection portion 8 connects the movable portion 6 to the supportportion 5 on the second axis X2 so that the movable portion 6 isswingable about the second axis X2. That is, each connection portion 8serves as a torsion bar.

As illustrated in FIG. 3, each connection portion 8 is a flatplate-shaped member having a substantially rectangular shape in the planview and extends along the second axis X2. An end 8 a on the side of themovable portion 6 in each connection portion 8 increases in width as itapproaches the movable portion 6. Here, the width of the connectionportion 8 means the length, of the connection portion 8 in a directionorthogonal to the second axis X2 in the plan view. When the connectionportion 8 increases in width in at least one end and is connected to thesupport portion 5 or the movable portion 6, the connection portion 8 is,for example, a region until the width becomes 1.5 times a minimum widthW0. In FIG. 3, a boundary B between the connection portion 8 and thesupport portion 5 and a boundary B between the connection portion 8 andthe movable portion 6 are indicated by a two-dotted chain line. Theconnection portion 8 may be a region where the stress applied during theswing of the movable portion 6 with respect to the support portion 5 islarger than ⅔ times the maximum stress.

As illustrated in FIGS. 1 and 2, the movable portion 6 is a flatplate-shaped frame having a rectangular shape in the plan view and islocated at the inside of the support portion 5. The movable portion 6 isdisposed to face one main surface of the magnetic field generator 3 andto be separate from one main surface of the magnetic field generator 3.An arrangement portion 9 having a circular shape in the plan view isprovided at the inside of the movable portion 6. The mirror 2 isdisposed on the arrangement portion 9. That is, the mirror 2 is providedwith the movable portion 6. The frame 4, the support portion 5, themovable portion 6, the pair of connection portions 7, and the pair ofconnection portions 8 are integrally formed of, for example, silicon(Si).

The actuator device 1 further includes, as illustrated in FIG. 2, thecoil 11 provided with the support portion 5 and the coil 12 providedwith the movable portion 6. The coil 11 is buried in the support portion5 and the coil 12 is buried in the movable portion 6. Each of the coils11 and 12 is formed of, for example, a metal material such as copper(Cu). In FIG. 2, each wiring is indicated by a solid line in order tofacilitate understanding, but the wirings like the coils 11 and 12 arecovered by an insulation layer 52 and/or an insulation layer 53 whichwill be described later.

The coil 11 is wound a plurality of turns in a spiral shape in the planview. One end of a wiring 14 a is electrically connected to an inner endof the coil 11. One end of a wiring 14 b is electrically connected to anouter end of the coil 11. Each of the wirings 14 a and 14 b is formedof, for example, a metal material such as aluminum. Each of the wirings14 a and 14 b is provided on one connection portion 7 and extends fromthe support portion 5 to the frame 4. The other end of the wiring 14 ais electrically connected to an electrode 15 a provided with the supportportion 5 and the other end of the wiring 14 b is electrically connectedto an electrode 15 b provided with the support portion 5. Each of theelectrodes 15 a and 15 b is electrically connected to a control circuitor the like. The wiring 14 a three-dimensionally intersects the coil 11to pass over the coil 11.

The coil 12 is wound a plurality of turns in a spiral shape in the planview. One end of a wiring 16 a is electrically connected to an inner endof the coil 12. One end of a wiring 16 b is electrically connected to anouter end of the coil 12. Each of the wirings 16 a and 16 b is providedon the pair of connection portions 8, the support portion 5, and theother connection portion 7 and extends from the movable portion 6 to theframe 4. The other end of the wiring 16 a is electrically connected toan electrode 17 a provided with the support portion 5 and the other endof the wiring 16 b is electrically connected to an electrode 17 bprovided with the support portion 5. Each of the electrodes 17 a and 17b is electrically connected to a control circuit or the like. The wiring16 a three-dimensionally intersects the coil 12 to pass over the coil12.

Each of the wirings 16 a and 16 b includes a first wiring 21 provided oneach connection portion 8, a second wiring 31 provided on the supportportion 5, and a third wiring 41 provided on the movable portion 6.Hereinafter, the configurations of the first wiring 21, the secondwiring 31, and the third wiring 41 in the vicinity of one connectionportion 8 will be described with reference to FIGS. 3, 4, and 5. Becausethe configurations of the first wiring 21 and the like in the vicinityof the other connection portion 8 are the same as the configurations ofthe first wiring 21 and the like in the vicinity of one connectionportion 8, a description thereof will be omitted. The insulation layer52 (see FIGS. 4 and 5) is omitted in FIG. 3.

The first wiring 21 is formed of a first metal material. The firstwiring 21 is provided over the support portion 5, the connection portion8, and the movable portion 6. The first wiring 21 includes a firstportion 22, a second portion 23, and a third portion 24. The firstportion 22 extends along the second axis X2 on the support portion 5,the connection portion 8, and the movable portion 6. The second portion23 extends from an end on the side of the support portion 5 in the firstportion 22 to the other connection portion 7 on the support portion 5.The third portion 24 extends from an end on the side of the movableportion 6 in the first portion 22 to the one connection portion 7 on themovable portion 6. The extension direction of the first portion 22 andthe extension direction of the second portion 23 are orthogonal to eachother and the extension direction of the first portion 22 and theextension direction of the third portion 24 are orthogonal to eachother.

The first wiring 21 is electrically connected to the second wiring 31 ina first connection part 25 located at an end on the support portion 5.The first wiring 21 is electrically connected to the third wiring 41 ina second connection part 26 located at an end on the movable portion 6.The first connection part 25 is separate from the second axis X2 by apredetermined distance D1. The distance D1 is larger than ½ times theminimum width W0 of the connection portion 8. The second connection part26 is separate from the second axis X2 by a predetermined distance D2.The distance D2 is larger than ½ times the minimum width W0 of theconnection portion 8. The first portion 22, the second portion 23, andthe third portion 24 have the same width. The width W1 of the firstwiring 21 is ½ times or more the minimum width W0 of the connectionportion 8 and is ⅔ times or more in this example. Here, the width W1 ofthe first wiring 21 indicates the length of the first wiring 21 in adirection orthogonal to the extension direction of the first wiring 21in the plan view. In the first portion 22, the width indicates thelength of the first portion 22 in a direction orthogonal to the secondaxis X2 in the plan view. Additionally, the width W1 of the first wiring21 is, for example, about 50 to 100 μm.

The second wiring 31 is formed of a second metal material. One end ofthe second wiring 31 is electrically connected to the first wiring 21.The other end of the second wiring 31 is electrically connected to theelectrode 17 a. A wide portion 32 which has a width larger than that ofthe other portion is provided at one end of the second wiring 31. Thesecond wiring 31 is electrically connected to the first connection part25 of the first wiring 21 in the wide portion 32.

The third wiring 41 is formed of a third metal material. One end of thethird wiring 41 is electrically connected to the first wiring 21. Theother end of the third wiring 41 is electrically connected to the coil12. A wide portion 42 having a width larger than that of the otherportion is provided at one end of the third wiring 41. The third wiring41 is electrically connected to the second connection part 26 of thefirst wiring 21 in the wide portion 42.

The rigidity of the first metal material forming the first wiring 21 ishigher than the rigidity of the second metal material forming the secondwiring 31. The rigidity of the first metal material forming the firstwiring 21 is higher than the rigidity of the third metal materialforming the third wiring 41. In other words, the rigidity of the secondmetal material forming the second wiring 31 is lower than the rigidityof the first metal material forming the first wiring 21. The rigidity ofthe third metal material forming the third wiring 41 is lower than therigidity of the first metal material forming the first wiring 21.Examples of a combination of the first metal material and the secondmetal material are a combination of tungsten (W) (the first metalmaterial) and aluminum (the second metal material), a combination oftungsten (the first metal material) and copper (the second metalmaterial), a combination of tungsten (the first metal material) and gold(the second metal material), and the like. Examples of a combination ofthe first metal material and the third metal material are a combinationof tungsten (W) (the first metal material) and aluminum (the third metalmaterial), a combination of tungsten (the first metal material) andcopper (the third metal material), a combination of tungsten (the firstmetal material) and gold (the third metal material), and the like. Thefirst metal material may be an aluminum alloy (AL-Cu or the like),nickel (Ni), platinum (Pt), or the like.

In the actuator device 1, the width W1 of the first wiring 21 is largerthan each of the width W2 of the second wiring 31 and the width W3 ofthe third wiring 41. The thickness of the first wiring 21 is the same aseach of the thickness of the second wiring 31 and the thickness of thethird wiring 41. Thus, the cross-sectional area of the first wiring 21is larger than each of the cross-sectional area of the second wiring 31and the cross-sectional area of the third wiring 41. Here, the width W2of the second wiring 31 means the length of the second wiring 31(excluding the wide portion 32) in a direction orthogonal to theextension direction of the second wiring 31 in the plan view. The widthW3 of the third wiring 41 means the length of the third wiring 41(excluding the wide portion 42) in a direction orthogonal to theextension direction of the third wiring 41 in the plan view. Thecross-sectional area of the first wiring 21 means an area of across-section orthogonal to the extension direction of the first wiring21. The cross-sectional area of the second wiring 31 means an area of across-section orthogonal to the extension direction of the second wiring31. The cross-sectional area of the third wiring 41 means an area of across-section orthogonal to the extension direction of the third wiring41. Additionally, the width of the second wiring 31 is, for example,about 5 to 10 μm.

As illustrated in FIG. 4, the actuator device 1 further includesinsulation layers 51, 52, and 53. Each of the insulation layers 51, 52,and 53 is, for example, a silicon oxide film (SiO₂).

The insulation layer 51 is provided on the surfaces of the frame 4, thesupport portion 5, the movable portion 6, the pair of connectionportions 7, and the pair of connection portions 8. The first wiring 21is provided on the insulation layer 51. That is, the first wiring 21 isprovided on the support portion 5 via the insulation layer 51.

The insulation layer 52 is provided on the insulation layer 51 so as tocover the first wiring 21. The insulation layer 52 is provided over theframe 4, the support portion 5, the movable portion 6, the pair ofconnection portions 7, and the pair of connection portions 8. Theinsulation layer 52 includes a first opening 52 a which exposes asurface 25 a opposite to the support portion 5 in the first connectionpart 25. The first opening 52 a is a hole having a circular shape in theplan view. The first opening 52 a is separate from a corner 25 b of thefirst connection part 25 by a predetermined distance. The insulationlayer 52 covers the corner 25 b of the first connection part 25. Aregion 53 d corresponding to the corner 25 b in the surface opposite tothe support portion 5 in the insulation layer 52 is curved in a convexshape toward the opposite side of the support portion 5. Here, thecorner 25 b of the first connection part 25 means a portion along anouter edge of the surface 25 a in the first connection part 25 (i.e. aportion in which at least two surfaces of the first connection part 25intersect each other).

The second wiring 31 is provided on the insulation layer 52. That is,the second wiring 31 is provided on the support portion 5 via theinsulation layers 51 and 52. The wide portion 32 of the second wiring 31runs on the first connection part 25 to cover the first opening 52 a. Apart 32 a of the wide portion 32 is disposed inside the first opening 52a and is connected to the surface 25 a of the first connection part 25in the first opening 52 a. The wide portion 32 includes a concaveportion 32 b at a position corresponding to the first opening 52 a inthe surface opposite to the support portion 5. The concave portion 32 bis formed such that a part 32 a of the wide portion 32 enters the firstopening 52 a at the time of forming the second wiring 31.

An electric connection structure between the first wiring 21 and thethird wiring 41 is the same as the above-described electric connectionstructure between the first wiring 21 and the second wiring 31. That is,as illustrated in FIG. 3, the insulation layer 52 includes a secondopening 52 b which exposes a surface 26 a opposite to the movableportion 6 in the second connection part 26. The second opening 52 b is ahole having a circular shape in the plan view. The second opening 52 bis separate from a corner 26 b of the second connection part 26 by apredetermined distance. The insulation layer 52 covers the corner 26 bof the second connection part 26. A region corresponding to the corner26 b in the surface opposite to the movable portion 6 in the insulationlayer 52 is curved in a convex shape toward the opposite side to themovable portion 6. Here, the corner 26 b of the second connection part26 means a portion along an outer edge of the surface 26 a of the secondconnection part 26 (i.e. a portion in which at least two surfaces of thesecond connection part 26 intersect each other).

The third wiring 41 is provided on the insulation layer 52. That is, thethird wiring 41 is provided on the movable portion 6 via the insulationlayers 51 and 52. The wide portion 42 of the third wiring 41 runs on thesecond connection part 26 to cover the second opening 52 b. A part ofthe wide portion 42 is disposed inside the second opening 52 b and isconnected to the surface 26 a of the second connection part 26 in thesecond opening 52 b. The wide portion 42 includes a concave portion at aposition corresponding to the second opening 52 b in the surfaceopposite to the support portion 5. The concave portion is formed suchthat a part of the wide portion 42 enters the second opening 52 b at thetime of forming the third wiring 41.

The insulation layer 53 is provided on the insulation layer 52 to coverthe second wiring 31 and the third wiring 41. The insulation layer 53 isprovided over the frame 4, the support portion 5, the movable portion 6,the pair of connection portions 7, and the pair of connection portions8. The insulation layer 53 includes a concave portion 53 a at a positioncorresponding to the first opening 52 a in the surface opposite to thesupport portion 5. The concave portion 53 a is formed such that a partof the insulation layer 53 enters the concave portion 32 b at the timeof forming the insulation layer 53. The insulation layer 53 includes aconcave portion at a position corresponding to the second opening 52 bin the surface opposite to the support portion 5. The concave portion ofthe insulation layer 53 is formed such that a part of the insulationlayer 53 enters the concave portion of the wide portion 42 at the timeof forming the insulation layer 53.

As illustrated in FIG. 5, the movable portion 6 is provided with agroove portion 55 having a shape corresponding to the coil 12. An innersurface of the groove portion 55 is provided with the insulation layer51. A seed layer 56 is provided on the insulation layer 51 inside thegroove portion 55. The seed layer 56 is formed of for example, titaniumnitride (TiN). The coil 12 is disposed inside the groove portion 55 viathe insulation layer 51 and the seed layer 56. The coil 12 is formed byburying, for example, a metal material such as copper in the grooveportion 55 according to, for example, a damascene method. The insulationlayer 52 is provided to cover the coil 12 disposed inside the grooveportion 55. The third wiring 41 is electrically connected to the coil 12via an opening provided with the insulation layer 52 so that an innerend of the coil 12 is exposed.

A groove portion 13 is formed along the boundary between the seed layer56 and the surface on the side of the insulation layer 52 in the coil 12at the time of forming the coil 12. The insulation layer 52 includes agroove portion 52 c at a position corresponding to the groove portion 13in the surface opposite to the movable portion 6. The groove portion 52c is formed such that a part of the insulation layer 52 enters thegroove portion 13 at the time of forming the insulation layer 52. Thethird wiring 41 includes a groove portion 41 a at a positioncorresponding to the groove portion 12 a in the surface opposite to themovable portion 6. The groove portion 41 a is formed such that a part ofthe third wiring 41 enters the groove portion 52 c at the time offorming the third wiring 41. The insulation layer 53 includes a grooveportion 53 b at a position corresponding to the groove portion 12 a inthe surface opposite to the movable portion 6. The groove portion 53 bis formed such that a part of the insulation layer 53 enters the grooveportion 41 a at the time of forming the insulation layer 53.

In the actuator device 1, when a current flows to the coil 11, a Lorentzforce is generated in a predetermined direction by electrons flowing inthe coil 11 by a magnetic field generated by the magnetic fieldgenerator 3. Accordingly, the coil 11 receives a force in apredetermined direction. For this reason, it is possible to swing thesupport portion 5 about the first axis X1 by controlling the directionor the magnitude of the current flowing in the coil 11. Similarly, it ispossible to swing the movable portion 6 about the second axis X2 bycontrolling the direction or the magnitude of the current flowing in thecoil 12. Thus, it is possible to swing the mirror 2 about each of thefirst axis X1 and the second axis X2 which are orthogonal to each otherby controlling the direction or the magnitude of the current flowing inthe coil 11 and the coil 12. Further, it is possible to swing themovable portion 6 at a high speed at the resonance frequency level byapplying a current having a frequency corresponding to the resonancefrequency of the movable portion 6 to the coil 12.

In the above-described actuator device 1, the rigidity of the firstmetal material forming the first wiring 21 provided on the connectionportion 8 is higher than the rigidity of the second metal materialforming the second wiring 31 provided on the support portion 5.Accordingly, deterioration of the first wiring 21 provided on theconnection portion 8 is suppressed. Also, it is possible to suppress thedeformation (curving or the like) of the support portion 5 caused whenthe entire wiring provided on the connection portion 8 and the supportportion 5 is formed of the first metal material having high rigidity.Further, the first wiring 21 and the second wiring 31 are connected toeach other at the first connection part 25 located on the supportportion 5. Accordingly, stress applied to the first connection part 25is reduced and deterioration of the first connection part 25 issuppressed. Further, in the actuator device 1, the corner 25 b of thefirst connection part 25 is covered by the insulation layer 52 and thefirst wiring 21 and the second wiring 31 are connected to each other inthe surface 25 a opposite to the support portion 5 in the firstconnection part 25 exposed by the first opening 52 a of the insulationlayer 52. Accordingly, because stress applied from the first wiring 21to the second wiring 31 is reduced by the insulation layer 52,deterioration of the second wiring 31 formed of the second metalmaterial of which the rigidity is lower than that of the first metalmaterial is suppressed. Thus, according to the actuator device 1, it ispossible to suppress deterioration of the wirings 16 a and 16 b providedon the connection portion 8 and the support portion 5. Further, becausethe first wiring 21 and the second wiring 31 are directly connected toeach other, it is possible to reduce the resistance of the wirings 16 aand 16 b provided on the connection portion 8 and the support portion 5.

In the actuator device 1, the first connection part 25 is separate fromthe second axis X2 by a predetermined distance D. Accordingly, it ispossible to reduce stress applied to the first connection part 25 whilesecuring a region for providing another configuration (for example, thecoil 11) on the support portion 5. That is, it is possible to secure aregion for providing another configuration on the support portion 5compared to a case in which stress applied to the first connection part25 is reduced by securing a distance along the second axis X2 betweenthe first connection part 25 and the connection portion 8.

In the actuator device 1, the distance D is larger than ½ times theminimum width W0 of the connection portion 8. Accordingly, it ispossible to further reduce stress applied to the first connection part25 while securing a region for providing another configuration on thesupport portion 5.

In the actuator device 1, the cross-sectional area of the first wiring21 is larger than the cross-sectional area of the second wiring 31.Accordingly, it is possible to suppress an increase in resistance valueof the first wiring 21 even when the resistivity of the first metalmaterial forming the first wiring 21 is higher than the resistivity ofthe second metal material forming the second wiring 31.

In the actuator device 1, the width of the first wiring 21 is largerthan the width of the second wiring 31. Accordingly, it is possible tosuppress an increase in resistance value of the first wiring 21 bysecuring the cross-sectional area of the first wiring 21 whilesuppressing the torsion of the connection portion 8 from beingobstructed.

In the actuator device 1, the first opening 52 a is separate from thecorner 25 b of the first connection part 25. Accordingly, it is possibleto reliably reduce stress applied from the first wiring 21 to the secondwiring 31.

In the actuator device 1, the region 53 d corresponding to the corner 25b in the surface opposite to the support portion 5 in the insulationlayer 52 is curved in a convex shape toward the opposite side to thesupport portion. Accordingly, it is possible to further reduce stressapplied from the first wiring 21 to the second wiring 31.

In the actuator device 1, the rigidity of the first metal materialforming the first wiring 21 provided on the connection portion 8 ishigher than the rigidity of the third metal material forming the thirdwiring 41 provided on the movable portion 6. Further, the first wiring21 and the third wiring 41 are connected to each other in the secondconnection part 26 located on the movable portion 6. Further, the corner26 b of the second connection part 26 is covered by the insulation layer52 and the first wiring 21 and the third wiring 41 are connected to eachother in the surface 26 a opposite to the movable portion 6 in thesecond connection part 26 exposed by the second opening 52 b of theinsulation layer 52. Thus, it is possible to suppress deterioration ofthe wirings 16 a and 16 b provided on the connection portion 8 and themovable portion 6.

The actuator device 1 further includes the frame 4 which supports thesupport portion 5 and the movable portion 6 and the support portion 5 isconnected to the frame 4 to be swingable about the first axis X1orthogonal to the second axis X2. Accordingly, it is possible to swingthe movable portion 6 about each of two orthogonal axes.

The actuator device 1 further includes the mirror 2 provided with themovable portion 6. Accordingly, it is possible to use the mirror 2 forthe light scanning or the like by swinging the mirror about each of thefirst axis XL and the second axis X2.

In the actuator device 1, the second wiring 31 is connected to thesurface 25 a opposite to the support portion 5 in the first connectionpart 25 located on the support portion 5 in the first wiring 21.Accordingly, because the stress applied from the first wiring 21 to thesecond wiring 31 is released to the opposite side to the support portion5, it is possible to suppress deterioration of the second wiring 31formed of the second metal material having rigidity lower than that ofthe first metal material. That is, it is possible to prevent a problemin which the stress applied from the second wiring 31 to the firstwiring 21 and the reaction force from the support portion 5 intensivelyact on the end of the second wiring 31, which happens in a case in whichthe end of the second wiring 31 is interposed between the first wiring21 and the support portion 5. Also with this configuration, according tothe actuator device 1, it is possible to suppress deterioration of thewirings 16 a and 16 b provided on the connection portion 8 and thesupport portion 5.

While the embodiment of the present disclosure has been described above,an embodiment of the present disclosure is not limited to theabove-described embodiment. For example, the second wiring 31 may beelectrically connected to the first wiring 21 in the first connectionpart 33 located at the end on the support portion 5 similarly to a firstmodified example illustrated in FIG. 6. In the first modified example,the second wiring 31 is provided on the insulation layer 51. Theinsulation layer 52 is provided on the insulation layer 51 to cover thesecond wiring 31. The insulation layer 52 includes the first opening 52a which exposes a surface 33 a opposite to the support portion 5 in thefirst connection part 33. The insulation layer 52 includes a corner 33 bof the first connection part 33. The region 53 d corresponding to thecorner 25 b in the surface opposite to the support portion 5 in theinsulation layer 52 is curved in a convex shape toward the opposite sideto the support portion 5. The first wiring 21 is provided on theinsulation layer 52. The end of the second portion 23 in the firstwiring 21 runs on the first connection part 33 to cover the firstopening 52 a. A part 23 a of the second portion 23 is disposed insidethe first opening 52 a and is connected to the surface 33 a of the firstconnection part 33 in the first opening 52 a. Also in the first modifiedexample, it is possible to suppress deterioration of the wirings 16 aand 16 b provided on the connection portion 8 and the support portion 5similarly to the above-described embodiment. Further, the third wiring41 may be electrically connected to the first wiring 21 in the secondconnection part 26 located at the end on the movable portion 6 similarlyto the first modified example.

Similarly to a second modified example illustrated in FIG. 7, adiffusion layer 58 may be provided instead of the insulation layer 51.The diffusion layer 58 is provided with a region contacting the firstwiring 21 on the surfaces of the support portion 5, the movable portion6, and the pair of connection portions 8. The diffusion layer 58 is, forexample, a diffusion region formed by diffusing a p-type impurity on asurface of an n-type silicon substrate. Also in the second modifiedexample, it is possible to suppress deterioration of the wirings 16 aand 16 b provided on the connection portion 8 and the support portion 5similarly to the above-described embodiment. Further, according to thesecond modified example, because the diffusion layer 58 serves as a partof the first wiring 21, it is possible to reduce the resistance of thewirings 16 a and 16 b provided on the connection portion 8 and thesupport portion 5 while securing the insulation at the diffusion layer58. Further, when the first metal material is tungsten, the first wiring21 can be stably provided on the connection portion 8 because tungsteneasily adheres to the diffusion layer 58.

Similarly to a third modified example illustrated in FIG. 8, an end 8 bon the side of the support portion 5 in each connection portion 8 mayincrease in width as it approaches the support portion 5. In FIG. 8, aboundary B between the connection portion 8 and the support portion 5and a boundary B between the connection portion 8 and the movableportion 6 are indicated by a two-dotted chain line. Also in the thirdmodified example, it is possible to suppress deterioration of thewirings 16 a and 16 b provided on the connection portion 8 and thesupport portion 5 similarly to the above-described embodiment.

In the above-described embodiment, the first wiring 21, the secondwiring 31, and the third wiring 41 may be provided with the connectionportion 7 as well as the connection portion 8. In this case, the firstwiring 21 is provided on the connection portion 7 and the second wiring31 is provided on the frame 4 to be electrically connected to theelectrodes 15 a and 15 b or the electrodes 17 a and 17 b. Then, thethird wiring 41 is provided on the support portion 5 to be electricallyconnected to the coil 11 or the second wiring 31 of the above-describedembodiment. The connection portion 7 may have a linear shape. Theconnection portion 8 may have an arbitrary shape as long as the movableportion 6 is connected to the support portion 5 on the second axis X2 sothat the movable portion 6 is swingable about the second axis X2.

In the above-described embodiment, the insulation layer 52 is providedover the frame 4, the support portion 5, the movable portion 6, the pairof connection portions 7, and the pair of connection portions 8, but maybe provided at least so as to be interposed between at least the firstwiring 21 and the second wiring 31 or the third wiring 41. The shapes ofthe first opening 52 a and the second opening 52 b are not limited tocircular shapes. The first opening 52 a and the second opening 52 b mayhave, for example, a rectangular shape, a rhombic shape, or the like.Further, the first opening 52 a and the second opening 52 b may have,for example, a notch shape opened to the extension direction of thesecond portion 23 or the third portion 24.

A part of the first opening 52 a may contact the corner 25 b of thefirst connection part 25. Also with this configuration, because thecorner 25 b is covered by the insulation layer 52, it is possible toreduce stress applied from the first wiring 21 to the second wiring 31similarly to the above-described embodiment. A part of the secondopening 52 b may contact the corner 26 b of the second connection part26. Also with this configuration, because the corner 26 b is covered bythe insulation layer 52, it is possible to reduce stress applied fromthe first wiring 21 to the second wiring 31 similarly to theabove-described embodiment. A region corresponding to the corner 25 b inthe surface opposite to the support portion 5 in the insulation layer 52may not be curved in a convex shape and may be curved in, for example, aplane shape. Also with this configuration, it is possible to reducestress applied from the first wiring 21 to the second wiring 31similarly to the above-described embodiment. A region corresponding tothe corner 26 b in the surface opposite to the movable portion 6 in theinsulation layer 52 may not be curved in a convex shape and may becurved in, for example, a plane shape. Also with this configuration, itis possible to reduce stress applied from the first wiring 21 to thesecond wiring 31 similarly to the above-described embodiment.

The first connection part 25 may be separate from the second axis X2 bya predetermined distance and may not be separated therefrom by thedistance D1 larger than ½ times the minimum width W0 of the connectionportion 8. Similarly, the second connection part 26 may be separate fromthe second axis X2 by a predetermined distance and may not be separatedtherefrom by the distance D2 larger than ½ times the minimum width W0 ofthe connection portion 8. The second wiring 31 may not be provided withthe wide portion 32 and the third wiring 41 may not be provided with thewide portion 42. The third wiring 41 may be electrically connected tothe coil 12 via another member formed of a metal material.

In the first wiring 21, the first portion 22 and the second portion 23or the third portion 24 may intersect each other at an angle other thanthe perpendicular direction. Alternatively, the whole first wiring 21may straightly extend along the extension direction of the connectionportion. In this case, the first connection part 25 is located on thesecond axis X2. The first portion 22, the second portion 23, and thethird portion 24 may not have the same width. In this case, the width ofthe first wiring 21 means the minimum width or the maximum width of thefirst portion 22, the second portion 23, and the third portion 24.

The cross-sectional area of the first wiring 21 may be larger than thecross-sectional area of the second wiring 31 and the width W1 of thefirst wiring 21 may be smaller than the width W2 of the second wiring31. For example, the thickness of the first wiring 21 may be larger thanthe thickness of the second wiring 31, and thus the cross-sectional areaof the first wiring 21 may be larger than the cross-sectional area ofthe second wiring 31. Here, the above-described embodiment is preferablein that the torsion of the connection portion 8 can be prevented and themanufacturing can be facilitated. Similarly, the cross-sectional area ofthe first wiring 21 may be larger than the cross-sectional area of thethird wiring 41 and the width W1 of the first wiring 21 may be smallerthan the width W3 of the third wiring 41. The cross-sectional area ofthe first wiring 21 may be equal to or smaller than the cross-sectionalarea of the second wiring 31 or the third wiring 41.

The actuator device 1 may be used to drive an object other than themirror 2. The shape of the mirror 2 is not limited to the circularshape. The mirror 2 may have, for example, a rectangular shape, arhombic shape, or the like. In the above-described embodiment, theswinging (driving) of the mirror 2 is performed by an electromagneticforce, but may be performed by, for example, a piezoelectric element. Inthis case, a wiring for applying a voltage to the piezoelectric elementis provided instead of the coils 11 and 12. The magnetic field generator3 may be omitted.

The first axis X1 and the second axis X2 may not be orthogonal to eachother and may intersect each other. The actuator device 1 may swing onlyabout the second axis X2. In this case, the frame 4 and the connectionportion 7 may be omitted and an electrode to be electrically connectedto a control circuit or the like may be provided with the supportportion 5. The connection portion 8 may be a region where the width issmaller than 2 times the minimum, width W0. Alternatively, theconnection portion 8 may be a region where the stress applied during theswing of the movable portion 6 with respect to the support portion 5 islarger than ½ times the maximum stress.

In the above-described embodiment, the insulation layer 52 covers theentire corner 25 b of the first connection part 25, but may cover atleast a part of the corner 25 b. For example, the insulation layer 52may cover at least a portion of the corner 25 b in the first connectionpart 25 where the surface 25 a opposite to the support portion 5intersects the surface (in the above-described embodiment, the surfaceon the side of the other connection portion 7) on the side to which thesecond wiring 31 is drawn out. Even when the insulation layer 52 coversonly a portion in which the surface 25 a opposite to the support portion5 intersects the surface in which the second wiring 31 in the firstconnection part 25 is drawn in the corner 25 b, it is possible tosuppress deterioration of the wirings 16 a and 16 b provided on theconnection portion 8 and the support portion 5 similarly to theabove-described embodiment. The second wiring 31 may be drawn along thesecond axis X2 from, for example, the first connection part 25.Similarly to the corner 26 b of the second connection part 26, theinsulation layer 52 may cover at least a part of the corner 26 b.

REFERENCE SIGNS LIST

-   -   1 . . . actuator device, 2 . . . mirror, 3 . . . magnetic field        generator, 4 . . . frame, 5 . . . support portion, 6 . . .        movable portion, 8 . . . connection portion, 12 . . . coil, 21 .        . . first wiring, 25, 33 . . . first connection part, 25 a, 33 a        . . . surface, 25 b, 33 b . . . corner, 26 . . . second        connection part, 26 a . . . surface, 26 b . . . corner, 31 . . .        second wiring, 41 . . . third wiring, 52 . . . insulation layer,        52 a . . . first opening, 52 b . . . second opening.

The invention claimed is:
 1. An actuator device comprising: a frame; asupport portion formed in a frame shape and located at the inside of theframe; a movable portion located at the inside of the support portion; acoil disposed at the movable portion; a first connection portion whichconnects the movable portion to the support portion so that the movableportion is swingable; and a second connection portion which connects thesupport portion to the frame so that the support portion is swingable,wherein the first connection portion is formed with a first wiring whichincludes an impurity layer of a first conductivity type, wherein thefirst wiring is electrically connected to the coil, wherein the firstwiring includes a first portion located at the first connection portionand a second portion located at the movable portion, and wherein thecoil is made of a metal material and is electrically connected to thesecond portion of the first wiring.
 2. An actuator device according toclaim 1, wherein the first connection portion includes a region of asecond conductivity type.
 3. An actuator device according to claim 1,wherein a second wiring formed of a metal material is provided on thesupport portion and the second connection portion and the first wiringand the second wiring are electrically connected to each other.
 4. Anactuator device according to claim 3, wherein the second wiring includesa widened portion at an end electrically connected to the first wiring.5. An actuator device according to claim 1, wherein an end on a side ofthe movable portion in the first connection portion increases in widthas it approaches the movable portion and/or an end on a side of thesupport portion in the first connection portion increases in width as itapproaches the support portion.
 6. An actuator device according to claim1, wherein the actuator device is configured such that the movableportion swings at resonance frequency thereof.
 7. An actuator deviceaccording to claim 3, wherein a total length of the second wiring islonger than a total length of the first wiring.
 8. An actuator deviceaccording to claim 3, wherein the first wiring and the second wiring areelectrically connected to each other via a metal layer.
 9. An actuatordevice comprising: a frame; a support portion formed in a frame shapeand located at the inside of the frame; a movable portion located at theinside of the support portion; a coil disposed at the movable portion; afirst connection portion which connects the movable portion to thesupport portion so that the movable portion is swingable; and a secondconnection portion which connects the support portion to the frame sothat the support portion is swingable, wherein the first connectionportion is formed with a first wiring which includes an impurity layerof a first conductivity type, wherein the first wiring is electricallyconnected to the coil, wherein a second wiring formed of a metalmaterial is provided on the support portion and the second connectionportion, and the first wiring and the second wiring are electricallyconnected to each other, and wherein the first wiring includes a firstportion located at the first connection portion and a second portionlocated at the support portion, and the first wiring is electricallyconnected to the second wiring at the second portion.
 10. An actuatordevice according to claim 9, wherein the second portion of the firstwiring includes a part extending in a direction intersecting with anextending direction of the first connection portion.
 11. An actuatordevice according to claim 9, wherein the first wiring includes a thirdportion located at the movable portion and the third portion of thefirst wiring includes a part extending in a direction intersecting withan extending direction of the first connection portion.
 12. An actuatordevice comprising: a frame; a support portion formed in a frame shapeand located at the inside of the frame; a movable portion located at theinside of the support portion; a first connection portion which connectsthe movable portion to the support portion so that the movable portionis swingable; and a second connection portion which connects the supportportion to the frame so that the support portion is swingable, whereinthe first connection portion is formed with a first wiring whichincludes an impurity layer of a first conductivity type, and wherein thefirst connection portion has a linear shape and the second connectionportion has a meandering shape.
 13. An actuator device comprising: aframe; a support portion formed in a frame shape and located at theinside of the frame; a movable portion located at the inside of thesupport portion; a coil disposed at the movable portion; a firstconnection portion which connects the movable portion to the supportportion so that the movable portion is swingable; a second connectionportion which connects the support portion to the frame so that thesupport portion is swingable; and another first connection portion whichconnects the movable portion to the support portion so that the movableportion is swingable, wherein the first connection portion is formedwith a first wiring which includes an impurity layer of a firstconductivity type, wherein the first wiring is electrically connected tothe coil, and wherein the other first connection portion is formed withanother first wiring which includes an impurity layer of a firstconductivity type.
 14. An actuator device according to claim 13, whereinthe first connection portion includes a region of a second conductivitytype.
 15. An actuator device according to claim 13, wherein a secondwiring formed of a metal material is provided on the support portion andthe second connection portion, and the first wiring and the secondwiring are electrically connected to each other.
 16. An actuator deviceaccording to claim 13, wherein an end on a side of the movable portionin the first connection portion increases in width as it approaches themovable portion and/or an end on a side of the support portion in thefirst connection portion increases in width as it approaches the supportportion.
 17. An actuator device according to claim 13, wherein theactuator device is configured such that the movable portion swings atresonance frequency thereof.